Ingot mould apparatus



Sept. 11, 1956 J. c. KRUGER INGOT MOULD APPARATUS Original Filed Nov. 22, 1952 a x 4 a a a INVENTOR.

L Q- I I W ATTORNEY United States Patent 1N GOT MOULD APPARATUS John C. Kruger, Woodbridge, N. 3.; Susan Kruger, Elizabeth Westphal and Elsie Kravits, execunices of said John C. Kruger, deceased Original application November 22, 1952, Serial No. 322,049. Divided and this application September 4, 1953, Serial No. 378,447

2 Claims. (Cl. 22144) This invention relates to the moulding of ingots and more particularly to an improved mould and method of making it. A primary aim of the invention is the construction of an ingot mould adapted repeatedly to withstand the high temperature of molten metal without injurious distortion.

A further aim of the invention is to construct an ingot mould for use in conjunction with a water-cooling jacket or enclosure and in which practical provision is made for allowing the mould to elongate and contract while maintaining the jacketing enclosure effectively sealed against leakage of the cooling medium.

Still another aim of the invention is the development of a practical process of producing a smooth, true, interior finish to the mould whereby not only to facilitate removal of the ingot but to reproduce on the ingot a smooth surface devoid of wrinkles, pockets or other surface blemishes that ultimately are reflected in the product when the ingot is subsequently rolled or drawn. The method of producing such a mould tube is disclosed and claimed in my application Ser. No. 322,049, filed November 22, 1952, as to which the present application is a division.

In attaining the objectives of the invention it is proposed to construct the mould in the form of a long tube, which may be round, square, or other suitable cross-section, and to circulate a cooling medium such as water around substantially the entire length of the tube. In the instant disclosure the tube is on the order of five feet long and approximately four inches square, with rounded corners. This tube has a wall thickness of onehalf inch, and is formed with a gradual taper, on the order of /s inch in the five foot length. One end of the tube, preferably the larger end, has a flange welded thereto which may be bolted to a similar flange provided at the end of a larger diametered jacketing tube. The mould tube extends within the jacket tube and is provided at its other'end with a flanged portion that is turned back and forms a short skirt around and spaced from the end portion of the mould. The outer surface of the skirt portion is turned cylindrical and is fitted to the cylindrical Wall portion of the jacket tube. Suitable packing material is inserted between the outer surface of the skirt portion and the inner wall of the jacket tube to provide a leakless joint but one that will allow the mould tube to elongate and contract. Water or other cooling medium is circulated through the cavity thus formed between the inner and the outer tubes and as this cavity extends substantially the entire length of the mould the mould is caused to be uniformly chilled, i. e., there are no areas or regions of higher heat than others. Furthermore as the inverted skirt portion of the central tube is spaced from the tube, the cooling medium is caused to reach the very end of the mould, and since the expansion joint and the packing material operate along the exterior of the skirt a short distance from the end, the same cooling medium tends to keep the skirt cool and the packing from burning out. Prior to this invention attempts were made to provide the water seal directly on the mould tube itself, where, because of the high beats and resulting tube expansion, the tube would be distorted before water tightness could be maintained. When a tubular mould has become distorted the ingot can be removed only with extreme difficulty and with the possibility of further distortions brought about by the hammering resorted to in attempting to release the ingot.

A mould for ingots should, therefore, be free to expand and contract, and to facilitate the release of the ingot should have its interior surface smooth and devoid of wrinkles or pockets. The taper should be slight, on the order of one-eighth inch in live feet, so as to provide a bar of substantially uniform sectional area that can be reheated uniformly and rolled or drawn uniformly. In accordance with this invention such a tube may be made by starting with a length of tube desired and which, within commercial tolerances, will be substantially uniform in its dimensions from end to end. The tube is then heated, in the case of copper to approximately 1600 F. and while hot, a gently tapered and polished mandrel is inerted into one end. The tube and the inserted mandrel are allowed to air cool for a short period and are then quickly cooled as by water quenching. During the air cooling, the tube shrinks onto the tapered mandrel and partakes of the shape thereof and when it is substantially quenched the differential in the coefficient \of expansion of copper and steel causes the mandrel to. shrink away from the copper and release the tube. The tube is again heated and the mandrel again inserted a further distance and the assembly again cooled and quenched. These operations are repeated until the tube has completely telescoped the mandrel thereby producing the highly important smooth, unwrinkled,'and gently tapered surface on the interior of the mould. Moulds that may beecome damaged or deformed after a period of service may be straightened and reconditioned in the same manner.

Other objects and advantages will be in part indicated in the following description and in part rendered apparent therefrom in connection with the annexed drawings.

To enable others skilled in the art so fully to apprehend the underlying features hereof that they may embody the same in the various ways contemplated by this invention, drawings depicting a preferred typical construction have been annexed as a part of this disclosure and, in such drawings, like characters of reference denote corresponding parts throughout all the views, of which:

Figure 1 of the drawings is a partial assembly of an ingot moulding apparatus embodying the invention, portions being broken away to clarify the construction.

Figure 2 is a transverse sectional view through the swivel journal mounting of the apparatus.

Figure 3 is a face view of the mould and water jacket removed therefrom.

Figure 4 is a view of an alternative form the exit end of the mould.

Referring to Figure l, the invention is shown in connection with typical moulding apparatus in which one or more swivel moulds are employed. Each mould assembly comprises an inner tube 10 and an outer tube 24) of such relative sizes as to provide a space 21 between for the circulation of a cooling medium such as Water. The outer tube 20 is provided with a flanged stem 22 that is removably secured, as by bolts not illustrated, to a swivel trunnion 23. The trunnion 23 is journaled in a relatively stationary support 24 and is maintained against endwise of cap for movement therein by means of a nut and washer 25 fitted to a reduced end portion 26 on the trunnion that projects through the end wall of the 27 connects with the support swivel journal with the support 24. A supply pipe and communicates with an internal annular channel 28 formed therein, and the swivel trunnion 23 is formed with a radial port 29 in the plane of the channel 28. Port 29 communicates with a longitudinal port 30 and the latter with another radial port 31 in a head end 23a of the trunnion. For convenience in drilling, the trunnion part 23a may be initially made as a separate piece and then welded to the axle part 23. Radial port 31 communicates with a pipe line 32 that leads to one end of the chamber 21 between the tubes and 20.

A return pipe 27a also is connectedwith the relatively stationary bearing 24 and communicates with another internal annular channel 28a thereof. Trunnion 23 is also formed with another set of ports 29a, a, 31a similar to but separate from those previously described, which communicates with pipeline 32a and the other end of the chamber 21 between the two tubes. By these means water under pressure may be caused to circulate between the tubes in any angular position of the mould in relation to the support 24. p

The inner tube 10, which is the mould tube, is gently tapered throughout its length, and one end, preferably its larger end, is provided with a welded-on flange 11 adapted to be bolted fast to a similar flange provided at one end of the outer tube 20. In the form illustrated in Figure 1, the flange 11 and tube 10 are recessed as at 12 to receive a toe end-cap 13. The cap 13 shoulders on the bottom of the recess 12 and is formed with a tapered cavity 13:: that produces a tapered lead on the ingot for roll gripping. The cap 13 may be removably secured to the mold as by a straddling strap 14 and hand screw v15 arranged to operate in the strap and against the cap.

In Figure 4 a hinged cap construction is illustrated in which the tube flange 11 is provided with pivot lugs 16 and a pair of bail lugs 17. A cover member 18 is pivoted as at 180 to the lugs 16 and is formed with a toe cavity 19 that registers with the tube when the cap is closed, as shown. The cover member 18 also carries a cap-tightening cam 18b that progressively enlarges from a starting point near the pivot 18a toward a finishing point slightly beyond the central longitudinal axis of the tube assembly. The lugs 17 on the flange 11 form pivotanchors for a bail Wire 17a that is constructed to overlay the cam 1811. Movement of the bail circumferentially along the cam surface will thus effect a clamping or unclamping of the hinged cap 18.

The opposite end of the mould tube 20 is formed with an integral flange or skirt that extends part way back from the end of the tube and is spaced therefrom so as to provide a chamber 41 between the skirt and the tube in open communication with the chamber 21 between the tubes 10 and 20. The outer surface of the inverted flange 40 is finished cylindrically and slidingly fitted to the outer tube 20. To provide a water seal, and an expansible joint, the outer tube is recessed as at 20a to receive a packing gland ring 2% and a packing material 20c. A complementary packing gland ring 20d is inserted on the packing material 200 and drawn up relativelytight by means of screws 20e that are screw threaded into a flange 20f on the end of the outer tube 20. As the screws 20e are tightened the packing material 200 is compressed in the annular pocket defined by the outer wall of the skirt 40, inner wall of tube 20, and the opposed end walls of the rings 20b and 20d, and an effective yet expansible seal is provided at that end of the water chamber. It will be seen'that the seal of this invention is spaced from the mould proper and not in direct contact therewith, that the cooling medium may circulate to the extreme end of the mould whereby to secure uniform cooling effects through out the length of the ingot, that the mould proper may elongate and contract freely, and that the clamping force applied on the packing material need be only moderate because the gland is maintained relatively cool, and such force as may be applied, has no distorting effect upon the mould proper.

When the apparatus has been set up and is ready for use, a funnel or pouring cap 36 is placed upon the open end of the mould. The cap 36 functions also as a riser, and is fashioned with a pilot extension 37 that centers the cap with the bore of the mould tube, and with a perforated partition wall 38 for screening out slag. If desired, side lugs 39 may be provided on the cap by which it may conveniently be handled. A smooth straight bore in the mould tube is a critical factor in the casting of an ingot, and I have found that the best way to construct such a mould is to form the mould from a section of seamless tubing and to produce a gentle taper therein from end to end, by progressively deforming the tube. My aforesaid application discloses and claims a preferred method of forming a mold tube. Briefly the method comprises the heating of a length of seamless tubing to a temperature on the order of 1600 F. and thereafter dropping into one end a relatively heavy gently tapered steel mandrel. The expansion factor of the tube will allow the falling mandrel to enter part way after which it is allowed to cool slightly and then is quenched. The shrinkage of the tube onto the tapered mandrel causes -a partial deformation of the tube. Thereafter the mandrel is withdrawn from the tube and the latter reheated and the mandrel again caused to fall a further distance into the expanded tube. The steps of air cooling and quenching are again'performed on the reheated tube.

The heating of the tube, dropping in of the mandrel, the shrinking and quenching operations are repeated as many times as may be necessary progressively to taper the tube its full length. I have found that the tapering of a tube 53 inches long usually requires four such shrinking processes to complete it to the stage where the lead end Without further analysis, the foregoing will so fully reveal the gist of this invention that others can, by applying current knowledge readily adapt it for various utilizations by retaining one or more of the features that, from the standpoint of the prior art, fairly constitute essential characteristics of either the generic or specific aspects of this invention, and therefore, such adaptations should be and are intended to be, comprehended within the meaning and range of equivalency of the following claims.

Having thus revealed this invention, I claim as new and desire to secure the following combinations and elements, or equivalents thereof, by Letters Patent of the United States:

1. An ingot mould comprising a relatively long slender tube having an anchor flange at one end and an inverted turned-back annular skirt portion at its other end, said long slender tube forming the inner wall of the mould and its said skirt portion being spaced away from the walls of the mould tubeproper, a water-jacketing tube cooling medium, the said cavity between the tubes being in open communication with the space between the inverted skirt portion of the mould tube and the tube proper whereby the cooling medium also tends to keep the packinggland means from overheating when the mould is in use, and means carried by the water-jacketing tube for compressing the packing gland means to effect a seal between the exterior of said skirt portion and the interior of the water-jacketing tube and whereby the mould tube proper remains unaflected by the forces of compression 5 exerted upon said packing gland.

2. The combination of claim 1 in which the inverted skirt portion of the mould tube overlays in spaced relation a substantial portion of the axial length of the mould tube and the said packing gland is effective on the exterior 10 of and at a region intermediate the ends of the said skirt.

References Cited in the file of this patent UNITED STATES PATENTS 

